For me textbooks are best consumed as a pdf. I don't kill my back, I don't kill my wallet, and I can ctrl-f through the entire book and annotate as needed. I throw it on a flashdrive on my keys and I can pass it around to classmates.

Any other kind of book and I'm reaching for print. It's much more satisfying to bang out 50 pages in a novel and see the bookmark move deeper into the book than to scroll scroll scroll through an ebook.